Problem: In her history class, Stephanie took 4 quizzes. Her scores were 97, 87, 81, and 87. What was her average score on the quizzes?
Explanation: The average is the sum of her scores divided by the number of scores. There are 4 scores and their sum is $97 + 87 + 81 + 87 = 352$ Her average score is $352 \div 4 = 88$.